HaeDong Kim, John Carlson, and Sydney Nelson. “Towards a Three-Dimensional Hardening of Schools to Promote Effective School Safety Practices in the United States: A Systematic Review”. Advances in Social Sciences Research Journal 8, no. 8 (August 17, 2021): 147–162. Accessed November 23, 2024. http://116.203.177.230/index.php/ASSRJ/article/view/10614.